Apparatus for treating steel rod or wire



United States Patent 1 1 3,539,167

[72] Inventor George W. Ashton References Cited Totley, Sheffield, England UNITED STATES PATENTS pp 658,747 1,852,144 4/1932 Brogdenetal ll8/423X 1 1 PM i 8 1,906,400 5/1933 Moon 11s/423x 1 Famed 1 2,000,292 5/1935 Miller.... 19s/41x 1 2 The Temvlmmugh Wing M1115 Llm'ted 2,008,200 7/1935 Clauss 198/41 sgx g ggfi 2,525,203 10/1950 BOSIIOem 148/156X 2,525,603 10/1950 1611166161.... 118/428X Prwmy 2- 2,717,125 9/1955 Rayburn.... 242/45x r 5,105,237 91963 4 311 36,398/66 and 987/67 Cum 2 2/83) [54] APPARATUS FOR TREATING STEEL ROD OR Primary Examiner-John P. Mclntosh Attorney-Sughrue, Rothwell, Mion, Zinn & MacPeak ABSTRACT: The patenting and particularly the lead patenting of rod or wire is effected by forming the rod or wire'in'to overlapping loops and passing these through a liquid bath in which there are magnetic rollers. When the bath is of lead the loops are conveyed into it over magnetic rollers, carried through it under magnetic rollers and carried out of it by further magnetic rollers.

Patented Nov; 10, 1970 Shet of 4 Patented Nov. 10, 1970 3,539,167

Patented Nov. 10, 1970 Sheet or 4 APPARATUS FOR TREATING STEEL ROD OR WIRE coiled while still hot, and then for subsequent treatments it isuncoiled, treated while travelling as a straight strand at low speed and coiled again.

A recent practical development comprises forming the rod into a series of overlapping nonconcentric loops which are carried forward by a conveyor on which they may be treated. Such overlapping loops of rod or wire can conveniently be produced from a travelling strand by apparatus which may be called a reeler and which may be of any convenient kind. The formation of the rod or wire into overlapping loops gives considerable advantages so far as throughput is concerned, since a greater weight of steel can be treated, for example air-patented, in a given time. However, it has not hitherto been possible to subject the rod or wire to any treatment in a hot liquid bath, say at a temperature of 550C, such as in involved in lead patenting and similar liquid patenting of steel, while in the form of overlapping loops. It is indeed possible to carry the overlapping loops through a liquid on a rubber or similar frictional belt, but such a belt will not normally withstand the high temperature involved in patenting operations. If the loops are pulled through the bath by tension instead of being carried on a belt, they become distorted and their pattern'is lost. if they are carried on a steel or similar conveyor, the liquid lubricates the steel so that it is no longer adequately frictionally engaged by the conveyor, particularly when moving downwards or upwards out of the bath.

The problem thus presented is solved, according to the invention, by the use of magnetic attraction. At least while being conveyed out of the bath, and preferably while being conveyed through it, the loops are magnetically attracted to the conveyor so that they do not slip on it.

Preferably the conveyor at the outlet end of the bath is a roller conveyor in which some, but more advantageously all, of the rollers are magnetic, that is to say include permanent magnets.

The loops are preferably similarly magnetically attracted while being conveyed through the bath in a horizontal path.

The magnetic rollers may take various forms, depending on the gauge of the rod or wire, the diameter of the loops and the nature of the liquid bath. It is preferred to make them composite, each consisting of magnetic sections separated by nonmagnetic spacers on a spindle. The spacers may themselves simply be tubes but preferably are abrasive discs of the same diameter as the magnetic sections so as to assist in the conveying. Suitable abrasive materials for such discs are silicon carbide and alumina. The number of magnetic sections on a spindle varies particularly with the length of the spindle, which in turn depends on the diameter of the loops.

The total number of rollers depends of course on the length of the bath, which is in turn determined by the metallurgical requirements'and by the speed of travel of the loops, and which may, for example, be from 30 to 40 feet. The spacing between the spindles of successive rollers may be, for example, 6 inches.

It is not necessary for all the rollers in a conveyor to be magnetic. Some may be replaced by rollers which are abrasive or spiked. For example each alternate roller may be magnetic and the remainder abrasive or spiked, particularly along a horizontal path. The advantage of economy is obtained since magnetic rollers are very expensive. An abrasive roller may be formed by a number of abrasive discs on a spindle. A spiked roller may consist of a mild steel cylinder 3 inches in diameter with spikes each one-half inch long projecting from it, each spike being of three-sixteenths inch base diameter, and the spacing between the spikes being 1 inch.

One of the treatments often applied to rod or wire is lea patenting (immersion of the rod or wire in molten lead,

usually at 550C). In conveying the rod or wire in the form of overlappingloops through such a bath there is not only the problem of slip but also a further problem presented by the fact that steel floats on lead. This further problem is solved by v causing the loops, when in the bath, to engage the underside of a conveyor, against which they are forced by. the upthrust from the lead. Advantageously this conveyor also magnetically attracts the loops.

The invention includes a process in which rod or wire in the form of overlapping loops is patented by passage through a liquid bath intoand out of which it is moved by a conveyor to which it is attracted by magnetic force. While this liquid may be a fused salt bath such as is also used for patenting, it is preferably molten lead.

The preferred apparatus according to the invention and one modification will now be described by way of example with reference to the accompanying largely diagrammatic drawings, in which:

FIG. 1 shows the layout of a plant for the lead patenting of rod as it is produced in a rod mill;

FIG. 2 is a central vertical section through a tank for the lead bath and the conveyors on a somewhat larger scale;

FIG. 3 is a plan corresponding to FIG. 2; but showing only the conveyors and a supporting frame;

FIG. 4 is a section on the line lV-lV in FIG. 2 and is on a larger scale;

FlG. 5 is a section through a magnetic section of a roller;

FIGS. 6 and 7 are respectively an elevation and a plan of the tank with the supporting frame removed; and

FIG. 8 is an elevation of a modified form of apparatus.

In the plant shown in FIG. 1 rod 1 is passed through a reeling device 2. This device can be of any convenient kind, but is shown as of the kind that rotates about a horizontal axis, and it converts the rod into loops which are shown at 3 as falling onto a slat conveyor 4. The rod is thus carried forward on this conveyor in the form of nonconcentric overlapping loops 5, and passes onto a conveyor composed of magnetic rollers 6 which present a downwardly inclined track into a tank 7 containing a bath of molten lead 8. The track formed by the rollers 6 leads the loops 5 to the underside of a conveyor composed of magnetic rollers 9. The loops pass under and are conveyed by this conveyor, which leads them to the upper side of a further conveyor 10 formed by magnetic rollers 11 which present an inclined track, magnetic rollers 12 which present part of a horizontal track and nonmagnetic rollers 13 which form the remainder of this track. These rollers 13 deliver the overlapping loops to a coiling device 14 of any convenient kind. Alternatively the rod can be cooled on the rollers 13 to a temperature at which it can pass onto a rubber belt, and still in the form of loops be carried by this belt through a pickling tank.

FIGS. 2 to 5 show the lead bath and conveyors on a larger scale, though still essentially diagrammatically. The tank 7 is housed in a casing 15 constructed to support a frame 16 which can be removed as a whole for maintenance. This frame is composed of beams 17 and 18 spanned by cross members 19 and is supported at its ends by the end walls of the casing 15. The rollers are all mounted on spindles, and the bearings of those rollers that'lie within the casing 15 are secured to the beams 17 and 18. As shown by FIG. 4, bearings 20 for the spindles 21 of the rollers 6 are secured to the underside of the beams 17 and 18, and bearings 22 for the spindles 23 of the rollers 9 are secured to the upper sides. The rollers are all positively driven from a common driving shaft 24 outside the casing, each roller being driven from the next by chain and sprocket drives diagrammatically shown at 25 in FIG. 3. As shown in FIG. 4, each spindle carries two sprockets 25 and 26. With such a construction, it is unnecessary for any driving connections to pass through the walls of the tank.

Each of the magnetic rollers comprises magnetic sections spaced apart on the'spindle by abrasive discs of the same diameter. In the rollers shown there are six magnetic sections 27, each 4 inches long axially, between end abrasive discs 28 and spaced apart by further abrasive discs 29. A magnetic section 27 is shown in detail in FIG. 5, and consists of a hollow cylindrical magnet 30 surrounded at each end by a steel sleeve 31 constituting a pole piece. The annular gap between the two pole pieces is filled by a spacer 32 of stainless steel to prevent any accumulation of metal particles in it. These parts of each magnetic section are held together by bolts 33.

The spacers 28 not only serve as nonmagnetic sections between magnetic sections, but also assist in the conveying of the loops.

It will be seen from FIG. 4 that in the middle of the roller there are three abrasive discs 29 between the adjacent magnetic sections 27, this central length, which may be about 6 inches long, being devoid of any magnetic section. The reason for this feature is that the passage of each loop from one magnetic roller to the next, or from the last magnetic roller 12 to the first nonmagnetic roller 13, is much facilitated. As the leading edge or the trailing edge of a loop reaches a roller it makes contact with the central length of the roller, and if there is a magnetic section in this length and magnetic attraction is such that the leading edge tends to wrap itself around the roller rather than continue towards the next roller, and the trailing edge is held back by the magnetic attraction. By omitting any central magnetic section, these tendencies are so much reduced that it is found in practice that there is no difficulty at all in the passage of a loop from the one roller to the next.

There is little tendency for the loops to slip over the downwardly inclined conveyor formed by the rollers 6, but it is desirable that these should be magnetic because the loops tend to continue in their horizontal path, and magnetic rollers pull them in turn off the conveyor 4 into the downward path. In addition, the magnetic attraction facilitates the entry of the loops into the lead bath.

When the leading loop enters the bath and leaves the last roller 6, the upthrust of the lead may not be enough to bend this loop into contact with the first roller 9. To ensure that the loop passes into contact with this roller, two guide rails 34 are provided, being secured to the transverse frame members 19. Each of these rails 34 has a downwardly inclined lip 35 engaged by the leading edge of the first loop so that this is directed upwards into the desired path.

The guidcrails, being part of the frame 16, are also useful during maintenance or repair; to test the apparatus before using it again, it may be desirable to pass loops through it in the absence of molten lead, or while the frame is outside the casing, and the guide rails then hold the loops if they should tend to fall downwards.

: In carrying out lead patenting according to the invention the speed of travel. of the loops and the length of the bath should be such that the residence time in the bath at 550C. is about half a minute. The steel loops may be at a temperature of about 750C. as they approach the bath, so that the heat given up by the loops to the bath is substantial. Accordingly the bath should be cooled so as to maintain it at about 550C.

' Thiscooling may advantageously be effected by pumping lead from the outlet end to the inlet end with the result that there is free flow of lead in the body of the bath from the inlet end to the outlet end. This is valuable in assisting the travel of the loops through the bath.

The preferred means for setting up this circulation of lead are shown in FIGS. 6 and 7. At the outlet end the tank 7 has a lateral pocket 36 in which a centrifugal pump 37 is mounted to rotate about a vertical axis, being driven by a motor 38 which is carried by a bracket 39. The pump has an inlet pipe 40 the mouth of which is in the middle of the tank 7 and close to the top of the lead bath 8. The-pump 37 discharges into a pipe 41, from which parallel pipes 42 branch and extend to the inlet end of the tank. The pipes 42 rest on transverse tubes 43 which span the bottom of the tank and the ends of which are welded into openings in the sides of the tank. Cooling water flows from a manifold 44 to a header 45 through these tubes 43 so that the lead flowing in the pipes 42 is cooled.

lt is also necessary to provide means for initially heating the lead. Most conveniently, these comprise electrical immersion heaters inside the bath as diagrammatically shown at 46. There may be any desired number of such heaters along the sides of the bath. If desired heaters may be arranged outsid the bath instead of inside it. v

Of course, all the parts of the apparatus that are to be immersed in lead or in any corrosive liquid must be made of material resistant to the action of that liquid.

It is possible to convey the loops through molten lead by an endless toothed conveyor or several such conveyors in paral lel, but it is not'feasible for any such endless conveyor to work partly immersed and partly out of a bath of molten lead because of the risk of lead being carried out of the bath and freezing on the conveyor. For this reason the arrangement of magnetic rollers described above is much preferred. However, once the loops have been introduced into the lead bath, the upthrust of the lead is enough to urge them into engagement with a conveyor, and accordingly the magnetic rollers in the bath may be replaced by an endless toothed conveyor wholly immersed in the lead bath. This modification is shown diagrammatically in FlGS. 8 and 9, in which magnetic roller conveyors 47 and 48 are provided at the inlet and outlet ends of the bath, and a toothed chain belt 49 running round chain wheels 50 and working wholly in the molten lead conveys the loops throughout most of their travel in the bath. The belt may extend across the loops'as shown, or be replaced by two or more parallel toothed chains.

I claim:

1. An apparatus for use in treating magnetizable rod or wire while formed into overlapping set predetermined nonconcentric loops, the apparatus of the type having a tank for containing a treating liquid, means for conveying the wire loops to and from the treating liquid on a conveyor path, the improvement for treating the wire in a high density, high temperature liquid in the tank, the high density liquid having a density higher than the magnetizable loops so that the loops tend to float, comprising: permanent magnetic rollers located in the high density, high temperature liquid at least partially below the surface and above the conveying path for the wire loops, the permanent magnetic rollers magnetically holding the wire loops while submerging and conveying them through the high density liquid without disturbing the relative loop position.

2. An apparatus as in claim 1, wherein the means for conveying the loops to and from the treating liquid include additional magnetic conveyor rollers located below the convey path for the wire loops and positioned on an incline for magnetically holding the wire loops in a set predetermined loop position as they are lead to and from the tank.

3. An apparatus according to claim 1 in which all the rollers are mounted in a frame removable from the tank.

4. An apparatus according to claim 3 in which the frame includes guide rails extending beneath the conveyor in the bath and formed with lips to assist in leading the loops into contact with that conveyor.

5. An apparatus according to claim 1 including initially heating the lead in the bath.

6. An apparatus according to claim 1 including means for cooling the lead during the passage of the loops through the bath in order to maintain the bath at a constant temperature.

7. An apparatus according to claim 6 in which the means for cooling the lead comprise a pump arranged to draw lead from the top of the outlet end of the bath, and heat-exchange pipes into which the lead is forced by the pump and which deliver it to the inlet end of the bath.

8. An apparatus for use in treating rod or wire with a high density, high temperature liquid comprising:

means for forming the wire into overlapping nonconcentric loops;

a tank for a high density, high temperature liquid;

means for conveying the wire loops to and from the liquid;

and

means for conveyor roller means having a permanent magnetic field located in the liquid tank above the wire loops forsubmerging the wire loops and conveying them through the high density liquid, the conveyor roller means comprising alternate sections of magnetic and abrasive material.

9. An apparatus for use in the lead patenting of rod or wire comprising means for forming the rod or wire into overlapping nonconcentric loops, a tank for a bath of molten lead, a conveyor in the tank and arranged to work wholly within the bath, a roller conveyor including magnetic rollers for leading the overlapping loops into the bath and beneath the conveyor in the bath, and a roller conveyor including magnetic rollers for 

